For example, patent applications FR-2,876,751, FR-2,973,448 and WO-2009/081,042 describe devices which capture the energy produced by sea water forces. These devices are made up of a floating support structure on which a pendulum is movably mounted with respect to the floating support. The relative motion of the pendulum with respect to the floating support is used to produce electrical energy by an energy converter machine (an electrical machine for example). The converter machine operates as a generator and as a motor. Indeed, in order to provide a torque or a force driving the mobile energy source, power is supplied to the converter machine to bring it into resonance with the waves (motor mode). On the other hand, to produce a torque or a force that withstands the motion of the mobile source, power is recovered via the converter machine (generator mode).
The motion of the mobile source is thus controlled by the energy converter machine to promote energy recovery. In order to optimize the electrical energy recovered by wave energy conversion systems, various converter machine control methods have been considered. Some are not optimal because the wave motion prediction is not taken into consideration. Furthermore, these methods do not account for the energy losses which occur during energy conversion in the wave energy conversion system. For example, patent application FR-2,973,448 (WO-2012/131,186) describes such a method.
Other methods combine model predictive control with a wave motion prediction algorithm. However, these algorithms do not allow the energy losses consequent from energy conversion with the wave energy conversion system to be taken into account. This does not enable to an optimum control maximizing the recovered energy. For example, the following document describes such a method: Giorgio Bacelli, John Ringwood and Jean-Christophe Gilloteaux, “A control system for a Self-Reacting Point Absorber Wave Energy Converter Subject to Constraints”, in: Proceedings of 18th IFAC World Congress, International Federation of Automatic Control (IFAC), 2011, pp. 11387-11392.